Mass production furniture making has become commonplace. While a segment of the market still caters to niche customers willing to pay for handcrafted furniture, the majority of consumers now purchase middle to low-cost furniture, manufactured in large quantities, and sold through large outlets and home improvement stores. The search for cheaper building materials for manufacturing furniture has accompanied this move to mass production. Two preferred low-cost furniture building materials in present use are particle board and multi-density fiber board (MDF).
Particle board is comprised of wood chips mixed with glue-like binders and pressed into square shapes to form a composite board. MDF is comprised of fine sawdust mixed with binders and extruded into composite boards. Both particle board and MDF can be laminated with various wood layers or washable, scratch-proof exterior surfaces. These exterior surfaces give any furniture constructed therefrom the exterior appearance of fine wood or laminate, even though composite MDF or particle board is underneath.
In the area of cabinet making, hinged doors must be hung from the body of the cabinet. When cabinets were mainly constructed from solid woods, hinges using screws were adequate for hanging the cabinet doors and holding them onto the body of the cabinet through years of use. For many years, all hinges were of an "exterior variety", meaning that the hinge could be seen from the exterior of the cabinet. In recent years, hidden, "interior" hinges, have become popular, these types of hinges not being visible from the exterior of the cabinet. Hidden hinges are also popularly known as "European" style hinges, because most of these hinges were pioneered in Europe.
There presently exists U.S. patents which disclose and claim hidden hinges. Typical examples are those seen in U.S. Pat. Nos. 5,392,493 (Youngdale); 4,177,540 (Gorton); and 5,517,724 (Beneke). The hidden hinges disclosed in these patents are for wooden cabinets and comprise a recessed cup and screws to hold the hinge to the cabinet body. The recessed cup is embedded into the wood of the cabinet door and allows the pivot arm of the hinge a measure of space to rotate into, upon opening or closing the cabinet door. A support plate opposite the recessed cup, fastens with screws to the cabinet body, and serves as the anchor point for the pivot arm. While this design works well in solid wood cabinets, it is inadequate for cabinets built from composite materials such as particle board or MDF.
It has been found that if the prior art hinges previously described are used with composite materials, the support plate loosens over time, as the screws loosen. Unfortunately, once the screws loosen in particle board or MDF, they cannot be re-tightened. In fact, attempts at re-tightening screws in composites tends to cause them to loosen more, and eventually fall out completely.
A "demountable" exterior hinge manufactured by Amerock, Inc. of Rockfield, Ill., provides a hinge which remains solidly coupled to an MDF or particle board cabinet door through years of use. This hinge requires that two cavities be routered into the edge of a cabinet door at top and bottom locations with a router bit. The exterior demountable hinge is comprised of a visible, decorative, pivot pin located between the cabinet body and door. A bracket extends from the pivot pin and mounts to the body of the cabinet. An arm extends from the pivot pin, opposite the bracket, and couples to the cabinet door. Unlike the other prior art hidden hinges previously described herein, the arm does not have a support plate fastened with screws. Instead, the arm ends in a "door wing" comprised of a half-moon-shaped "connecting plate" bolted to a support plate. The connecting plate and support plate extend from the second arm in a parallel relation. A bolt holds the support plate and connecting plate together and spaces them apart with a small gap. The connecting plate slides into the cutout made in the cabinet door. A channel made by a router bit extends from the edge of the cabinet door to about halfway into the cutout, this channel for accommodating the bolt. The support plate rests upon the inside surface of the cabinet door. When the bolt is tightened, a portion of the composite material is "sandwiched" in the gap separating the connecting plate and the support plate, thereby holding the cabinet door solidly upon the exterior hinge. The doorwing does not rely on screws and does not have the attendant problems previously described regarding screw fastening to composites.
Presently, while the Amerock exterior hinge works well in particle board and MDF, there have been no similar hidden interior "European style" hinges which have performed similarly well. The Amerock hinges are not designed for hidden interior applications. Also, the Amerock hinges are designed for use in cabinets having a solid wood body and either composite or wood doors, because the bracket of the Amerock hinge is coupled with screws, which would be inadequate for coupling to a cabinet body made of composite material for reasons heretofore described.
The foregoing discussion reflects the state of the art of which the inventor is aware, and is tendered with a view toward discharging the inventor's acknowledged duty of candor in disclosing information which may be pertinent with regards to the patentability of the present invention. It is respectfully stipulated, however, that the disclosed information does not teach or render obvious, singly or when considered in combination, the inventor's claimed invention.